"A4A member airlines have no plans to cancel or suspend flights or operations as a result of FAA's announcement of 149 tower closures, and we continue to work cooperatively with the FAA to minimise any impact to the two million customers and 50,000 tonnes of cargo our members fly every day," says US airline industry body Airlines for America (A4A).

US transportation secretary Ray LaHood says: "We heard from communities across the country about the importance of their towers and these were very tough decisions. Unfortunately we are faced with a series of difficult choices that we have to make to reach the required cuts under sequestration."

The FAA will keep 40 small airport towers open that were on the list of 189 possible closures that it released in February. Local communities can elect to assume the cost of continued operations at their local tower if it is slated for closure, adds the agency.

There is no update to whether the FAA will eliminate midnight shifts at 60 towers, which include major airports like Chicago Midway and San Juan, as a result of the budget cuts, it says. This was included as a possible move in February.

The FAA must cut $637 million from its budget as a result of the sequester, which involves $85 billion in budget cuts across the US federal government this fiscal year from 1 March.